SDR ASAA2020081313015

Service difficulty report · Warning Light · Boeing 737990ER

Difficulty date: August 11, 2020
Submitted: August 13, 2020
Operation: Air carrier
Aircraft: N469AS
Make and model: Boeing 737990ER
Aircraft serial: 41702
Aircraft time: 23,187 hours, 7,482 cycles
System (JASC): 4900 · Airborne Auxiliary Power Unit (APU) System
Part: Warning Light
Condition: False Activation
Stage of operation: TX
How discovered: O
Nature of condition: N
Precautionary procedure: O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

AMBER FAULT LT CAME ON WHILE ATTEMPTING TO START THE APU ON ARRIVAL. GROUNDED - YES. FAULT CODES 49-31016 (OVERTEMP SHUTDOWN) AND 49-41012 (NO APU ROTATION SHUTDOWN) FOUND DURING TROUBLESHOOTING. OPENED COMPRESSOR PLELUM & INSPECTED FOR OBSTRUCTIONS AND DAMAGE, AIR INTAKE CLEAR, CW B737-900 FIM 49-40 TASK 803 & 49-40 TASK 811, OPERATED APU, STARTS NORMAL- APU HOLDS FULL ELECTRICAL & AIR LOAD.